In recent years, advancement is seen in the development of a light emitting device using, as the light source, an organic EL element which is employed as a light emitting element. An organic layer of the organic EL element has a configuration in which a hole injection layer, a light emitting layer, and an electron injection layer are stacked on top of one another.
Patent Document 1 discloses that an electron injection layer includes a salt of an acid of one or more types of metals that are selected from the group consisting of molybdenum, tungsten, vanadium, tantalum, titanium, and group IIb elements, with one or more types of alkali metals that are selected from the group consisting of potassium, rubidium, and cesium.
Patent Document 2 discloses that an electron injection layer includes at least one kind of an alkali metal, an alkaline earth metal, or salts thereof.